Probiotics and infection
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Probiotics and Infection: A Comprehensive Overview
Probiotics for Preventing Respiratory Infections
Acute Upper Respiratory Tract Infections (URTIs)
Probiotics have shown promise in preventing acute upper respiratory tract infections (URTIs). A meta-analysis of 13 randomized controlled trials (RCTs) involving 3720 participants revealed that probiotics significantly reduced the number of participants experiencing at least one episode of acute URTI (odds ratio (OR) 0.53) and the mean duration of an episode (mean difference (MD) -1.89 days) . Additionally, probiotics were associated with reduced antibiotic prescription rates and cold-related school absences . However, the quality of evidence was generally low, indicating a need for further high-quality studies.
Respiratory Tract Infections in Adults and Children
Probiotics may also reduce the risk of various symptoms of respiratory tract infections, including ear, nose, and throat infections, although the data are currently insufficient to make definitive clinical recommendations . Some studies have shown that probiotics can modulate immune function, which may contribute to their protective effects against respiratory infections Macfarlane2002Stavropoulou2020.
Probiotics in Hospitalized Patients
Clostridium difficile Infection (CDI)
Probiotics have been effective in preventing Clostridium difficile infection (CDI) in hospitalized adults taking antibiotics. A systematic review and meta-regression analysis of 19 studies with 6261 subjects found that the incidence of CDI was significantly lower in the probiotic group (1.6%) compared to controls (3.9%) . The effectiveness of probiotics was higher when administered closer to the first antibiotic dose, reducing the risk of CDI by over 50% . This highlights the importance of timely probiotic administration in clinical settings.
Liver Transplantation
In patients undergoing liver transplantation, probiotics combined with prebiotics significantly reduced infection rates post-surgery. A meta-analysis of four controlled studies involving 246 participants showed that the infection rate was 7% in the probiotic group compared to 35% in the control group . Probiotics also reduced the duration of hospital and intensive care unit stays, as well as the duration of antibiotic use .
Probiotics in Critical Illness
Nosocomial Infections
Probiotics have shown potential in reducing nosocomial infections in critically ill patients. A systematic review and meta-analysis of 30 trials with 2972 patients indicated that probiotics significantly reduced the overall number of new infections and the incidence of ventilator-associated pneumonia (VAP) . However, no significant effects were observed on mortality, length of hospital stay, or diarrhea, suggesting that more research is needed to fully understand the benefits of probiotics in critical care settings .
Probiotics in Postoperative Infections
Colorectal Cancer Surgery
Probiotics and synbiotics have been effective in reducing postoperative infections in colorectal cancer patients. A systematic review and meta-analysis of 19 high-quality RCTs involving 1975 patients found that probiotics significantly reduced total postoperative infections, including surgical site infections (SSI) and non-surgical site infections (non-SSI) . The treatment group also showed better outcomes in terms of inflammatory factors and intestinal dysbiosis .
Mechanisms of Action
Immune Modulation and Gut Barrier Function
Probiotics exert their beneficial effects through various mechanisms, including enhancing mucosal barrier function, direct antagonism with pathogens, and modulation of the immune system Macfarlane2002Isolauri2002. They can stabilize the intestinal barrier, stimulate the proliferation of intestinal epithelium, and increase mucus secretion and motility, which collectively help prevent bacterial translocation and subsequent infections Sawas2015Isolauri2002.
Gut-Lung Axis
Recent discussions have highlighted the "gut-lung axis," where the intestinal microbiota influences alveolar macrophage activity, thereby playing a protective role in respiratory infections . This underscores the interconnectedness of different body systems and the potential systemic benefits of probiotics.
Conclusion
Probiotics have demonstrated significant potential in preventing and managing various infections, including respiratory tract infections, CDI, and postoperative infections. Their mechanisms of action, primarily through immune modulation and gut barrier enhancement, make them a promising adjunct in clinical settings. However, the quality of evidence varies, and further high-quality studies are needed to establish definitive clinical guidelines for their use.
Sources and full results
Most relevant research papers on this topic
Timely Use of Probiotics in Hospitalized Adults Prevents Clostridium difficile Infection: A Systematic Review With Meta-Regression Analysis.
Probiotics given within 2 days of antibiotic initiation significantly reduce the risk of Clostridium difficile infection by over 50% in hospitalized adults.
Patients Receiving Prebiotics and Probiotics Before Liver Transplantation Develop Fewer Infections Than Controls: A Systematic Review and Meta-Analysis.
Prebiotics and probiotics before liver transplantation reduce the rate of infection, shorten hospital stays, and decrease antibiotic use.
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